Map-by-map comparison of the results from the different estimators for local (top), equilateral (centre), and orthogonal (bottom) f_NL for 99 maps from a set of realistic lensed simulations passed through the SMICA pipeline, described in Sect. 6.2, assuming the shapes to be independent. The horizontal solid line is the average value of the maps for KSW, and the dashed and dotted horizontal lines correspond to 1σ and 2σ deviations, respectively.